The present invention relates to a method and a device for hydraulically and selectively controlling a set of instruments or tools connected to a casing located inside a well drilled in the ground, particularly a horizontal well.
The invention also provides a valve allowing the method to be implemented, said valve being able to use the device according to the invention.
In particular, the invention is applied to exploitation in stages of geological formations or producing zones such as oil-bearing or gas-bearing producing zones. For this usage, the tools that may be used may be valves disposed in each of the formations or each of the producing zones and remote-controlled using the method or device according to the invention.
One noteworthy advantage of the invention is the reduction in the number of hydraulic lines that had to be used according to the teaching of the prior art. This advantage is particularly perceptible at the points where the hydraulic lines pass through seals (where these are present), these seals being for example of the packer type; from the standpoint of the space occupied by the lines along the casing, particularly at its periphery; for reducing the cost of the hydraulic lines and positioning them as allowed by the invention.
The invention applies in particular to production by horizontal wells. particularly in oil drilling, production by a well causes displacement of the various layers of liquids in the producing zone, a phenomenon called coning. In production in horizontal wells, undesirable fluids such as water generally arrive irregularly along the well so that a large portion of the liquid sought, such as oil, is not extracted from the formations.
There are two approaches to overcoming this drawback; several producing zones are created and equipped with means such as valves that allow the flowrate to be controlled; and the quality and quantity of the fluids coming from each of the producing zones are controlled. This control may be effected by instruments such as flowmeters and physical and/or chemical instruments for measuring fluids, disposed for example along the well or casing according to each of the producing zones.
The invention furnishes a device for hydraulically and selectively controlling a set of at least two instruments or tools connected to a casing located inside a well, the well having at least two different producing zones, said two instruments or tools being disposed according to eahc of said producing zones. This device is characterized in particular by having a first hydraulic line with branches to the instruments or tools and having distribution means such as a solenoid valve places on each of the branches and controlled independently of each other by a distribution means control element, the first hydraulic line being connected to a hydraulic power generator.
The distribution means control element may include an electrical line.
The electrical line may be connected to a first electrical connector located inside the casing and designed to cooperate with a second matching electrical connector connected to the surface of the ground by a transmission cable.
The two producing zones may be separated from each other in the well by a sealing element such as an annular seal.
The first hydraulic line may be connected to the surface of the ground by the outside of the casing.
The first hydraulic line may be connected to a first hydraulic connector located inside the casing and designed to cooperate with a second matching hydraulic element connected to the surface of the ground by a pipe.
The device may include a second hydraulic line which has at least one branch supplying one of said instruments or tools.
At least one of said tools or instruments may include a reservoir designed to contain a variable quantity of hydraulic fluid, the reservoir being connected by a branch to the first hydraulic line.
The first hydraulic line or the second hydraulic line may be connected to said casing by a hydraulic connection including at least one shutoff element. The shutoff element may be retractable. The first or second line may serve as a pipe for creating fluid circulation in the casing.
The invention also supplies a process for hydraulically and selectively controlling, in two circulation directions, at least two tools or instruments of a device connected to a casing located inside a well, the device also having a first hydraulic line with branches to a first and a second of the two tools or instruments, distribution means designed to modify the circulation of fluid in each of the branches and controlled independently of each other, and a hydraulic power generator connected to said first hydraulic line. In accordance with the process of the present invention, in order to selectively activate the first tool or instrument, the distribution means of the second tool or instrument are shut off in order to reduce fluid circulation in the branch of the second tool or instrument, the distribution means of the first tool or instrument are opened in order to increase fluid circulation in a branch of the first tool or instrument, and pressure is applied in the first hydraulic line in order to create a flow of fluid in the first direction in the branch of the first tool or instrument.
The first tool or instrument may permit circulation of hydraulic fluid in the two opposite directions and may include a reservoir designed to contain a variable mass of fluid, said reservoir being connected by the first of said branches to the first hydraulic line, and in order to produce, in the branch of the first tool or instrument, a flow in a second direction opposite the first direction, the distribution means of the first tool or instrument may be opened and the pressure in the first hydraulic line may be reduced.
In addition, a second hydraulic line may be used, which has at least one branch to at least one of the tools or instruments, and in order to produce, in the branch with the first hydraulic line of the tool or instrument connected to the second hydraulic line, fluid circulation in a first direction or in a second direction opposite the first, the distribution means of the tool or instrument connected to the two lines may be opened, and in the first or second line, pressures may be created to produce fluid circulation in the branch to the first line, in the first or second direction.
The second tool or instrument may permit hydraulic fluid circulation in the two opposite directions and may include a reservoir designed to contain a variable mass of fluid. Since this reservior is connected by the second of the branches to the hydraulic line, and return means enable the second tool or instrument to revert to an initial position, to selectively activate the second tool or instrument, the distribution means of the first tool or insturment can be closed in order to prevent circulation of fluid in the branch of the first tool or insturment. The distribution means of the second tool or instrument may be opened to permit fluid circulation in the branch of the second tool or instrument, the first hydraulic line may be pressurized in order to create, in the branch of the second tool or instrument, a flow of fluid in the first direction, and, in order to produce a flow in the second direction opposite the first direction in the branch of the second tool or instrument, the pressure in the first hydraulic line may be reduced. Once fluid circulation has been produced, in the first or second tool or instrument, in the first or second direction, the distribution means of the first or second tool or instrument may be shut off in order to prevent fluid circulation in the branch of the first or second tool or instrument.
When the method according to the invention is applied to selective production of a deposit, the first and second tool or instrument may be located on the casing and may be designed to modify the rate of production fluid transfer between the inside and the outside of the casing.
The distribution means may be controlled electrically by a cable connected to a first electrical connector located inside the casing, a second matching electrical connector may be introduced into and moved in the casing, which connector is connected to the surface of the ground by a transmission cable, and the first and second electrical connectors may be caused to cooperate in order to control the distribution means from the surface of the ground.
The hydraulic power generator may be disposed in the well in the vicinity of the tools or instruments.
The hydraulic line may be connected to a first hydraulic connector located inside the casing, a second matching hydraulic connector may be introduceds into and moved in the casing, which matching connector is connected to the surface of the ground by a pipe, the first and second hydraulic connectors may be caused to cooperate, and the hydraulic power generator may be located at the end of the pipe near the surface of the ground.
A pipe connected to said casing by a hydraulic connection may be located in the well, an element designed to shut off this connection may be disposed thereon, the pipe may be connected to the hydraulic generator, and the pipe may be used as the first or second hydraulic line.
The invention also provides a sliding jacketed valve usable for equipping casings of wells drilled into the ground.
The valve in particular allows, in a simple manner, selective production from geological formation traversed by the casing with the aid of a very small number of control lines. This reduction in the number of lines is particularly advantageous at the point where the lines pass through--these seals may be of the packer type--from the standpoint of the space occupied by the lines along the casing, particularly at its periphery and also reduction in the costs of installing these lines.
The sliding jacketed valve for production from wells drilled into the ground has an external cylindrical body designed to fit into a casing, an extension inside this body, a sliding jacket between the body and the extension, and allowing opening of the orifices that provide a connection between the inside and the outside of the valve, a thrust chamber delimited by the body, the extension, and one end of the jacket, the chamber being connected to hydraulic control means such as a line connected to a hydraulic generator.
This valve is in particular characterized by also having return means such as a spring acting on the jacket, whereby the hydraulic control means tend to move the jacket from an initial position against the action of the return means such as to change the apertures of the orifices, said return means being designed to return the jacket to the initial position in the absence of sufficient action on the part of the hydraulic control means.
The valve may comprise a safety jacket controlled mechanically by the inside of the casing and designed to change the apertures of the orifices.
The invention will be thoroughly understood and all its advantages will appear clearly from a reading of the description hereinbelow of which one embodiment is illustrated by the attached figures wherein: